It has been common to convert data representing contents, such as moving picture data, still picture data, and text data, into time series data, and record the converted time series data into information recording media including, e.g., optical disks such as CD-R discs, CD-RW discs, CD-MRW discs, DVD−R discs, DVD-WR discs, DVD-RAM discs, DVD+R discs, and DVD+RW discs, magneto optical disks such as MOs and MDs, magnetic disks such as HDs and FDs, and IC cards such as nonvolatile RAMs and flash ROMs. When recording the contents, an information recording medium suitable for the content to be recorded is selected. Also, an information recording device such as a CD drive, a DVD drive, an MO drive, an MD drive, an HD drive, an FD drive, or an IC card drive, applicable to the selected information recording medium is selected. The selected drive is used for recording and reproducing the content.
FIG. 10 shows layout examples of an information recording medium for recording and reproducing time series data in linear addressing.
This information recording medium has a recording/reproducing area divided into sectors of a fixed size. Areas shown in FIG. 10 are application level areas each having a size larger than the size of sectors. It is to be noted that the proportion of the size of the areas does not correspond to the proportion of the actual data volume of the areas.
Referring to (a) of FIG. 10, a recording area 40 of the information recording medium includes a Lead-In area 41 at the top. The Lead-In area 41 is the area from which reading of information recorded in the information recording medium is started when the information recording medium is loaded in an information reproducing device or an information recording/reproducing device. The Lead-In area 41 contains general information about the information recording medium such as information about the information recording medium itself and information about data layout.
The Lead-In area 41 is followed by a user recordable area 42 in which users can record content represented by time series data and the like. The user recordable area 42 is the only area where users can record data.
The address of the top sector of the user recordable area 42 is zero, and is represented as “LBA:0” (indicated by the arrow in FIG. 10). The user recordable area 42 has points called anchor points at addresses specified depending on file systems of operating systems.
The anchor points serve as marks for jumping to another area over areas on the way in response to an instruction. The user recordable area 42 may have one or more anchor points. In the example shown in FIG. 10, the anchor points are provided at the start position of a content area 44 and a start position of a Lead-Out area 46.
A file system area 43 in the user recordable area 42 is for defining stored location of individual files and directories, the size, time, attribute, etc. The file system area 43 is followed by the content area 44 where content represented by the time series data is recorded.
The content area 44 may be followed by a miscellaneous data area 45 where data excluding the content are recorded. The miscellaneous data area 45 is not necessarily required.
At the end, an area called as the Lead-Out area 46 is provided, which continues near the end limit of the information recording medium. The Lead-Out area 46 allows the information recording/reproducing device to recognize the end of a recording area 40 when recording/reproducing the content by receiving a light irradiated from an optical pickup and reflected by the information recording medium.
In many cases, the time series data representing the content occupy the greater part of the information recording medium. The areas provided in the information recording medium need to be continuous to each other. If there is non-recorded areas 47 as shown in FIG. 10 (b), regular information reproducing devices of reproduction-only type cannot reproduce the content. This indicates lowered compatibility of the information recording medium.
The time series data recorded in the information recording medium may be large-volume data containing, as the content thereof, images, sounds, maps, an encyclopedia or the like. Such large-volume data are often provided with index information items (index data) for referring to segmentation points of the recorded content. The index information items may be, for example, chapter images recorded together with a moving picture. The chapter images may be selected and prepared by, e.g., a producer of the moving picture or may be automatically created by the information recording/reproducing device, and are recorded as a part of data representing the moving picture into a CD (CD) or a DVD (Digital Versatile Disc) in which the data representing the moving picture is recorded.
In many cases, the chapter images selected by the producer correspond to important scenes of the moving picture. Accordingly, users can use the chapter images as the index information items and select one of the chapter images to playback the desired part of the moving picture.
However, the chapter images selected from the moving picture by the producer and recorded as the index information items in the user recordable area cannot always be effective index information items to the users as the users may have different tastes and preferences.
A technique is disclosed in Japanese Patent Laid-Open Publication No. 2001-76474 that sequentially replays chapter images as index information items so as to allow users to quickly overview content and select a desired chapter image, and thus replays the desired part of the content.